The provisions of the Illinois Administrative Procedure Act are hereby expressly adopted and shall apply to all administrative rules and procedure of the Department under this Act, except that in case of conflict between the Illinois Administrative Procedure Act and this Act the provisions of this Act shall control, and except that Section 5 of the Illinois Administrative Procedure Act relating to procedures for rulemaking does not apply to the adoption of any rules required by federal law in connection with which the Department is precluded by law from exercising any discretion.